1. Field of the Invention
This invention relates to a device for reducing or preventing snoring and, in particular, to an anti-snoring device which can be easily fit to patients having either a wide or a narrow dental arch.
2. Description of the Related Art
Snoring is normally the result of vibration of the uvula, soft palate, and adjacent structures during sleep and signals partial obstruction due to the narrowing of the upper airway at that site. In most cases, breathing is normal or only minimally impaired, and symptoms primarily concern sleep disturbance and the social consequences of snoring. In other cases, snoring is associated with the obstructive sleep apnea syndrome, a serious condition characterized by intermittent upper airway obstructions that require arousal for relief.
Various devices are known in the art for placement in the oral cavity and intended for to reduce snoring. Some investigators have provided devices which are arranged to seal the lips of the wearer, one to another, thus blocking air passage through the mouth. Others have recognized that portions of the uvula, soft palate, and adjacent structures vibrate during sleep, in response to the passage of air past these tissues, and attempt to minimize such vibrations by providing devices which sharply reduce the volume of air passing through the mouth, without necessarily completely blocking the mouth. However, if the nose is blocked, or partially blocked, this reduction of the airway increases the velocity of the air passing those tissues and snoring can actually increase.
Yet another type of prior art device is exemplified by the device of U.S. Pat. No. 1,674,336 to King. King intends that his device will maintain a plentiful supply of oxygen to the blood of a user during sleep, and even reduce snoring. His structure comprises an upper channel and a lower channel to receive the upper and lower teeth, respectively. The two channels are spaced apart vertically to prop the upper and lower front teeth apart and to define an air passage therebetween. Thus, in use, the device props the teeth of a user apart in a fixed position, which King claims opens the posterior airway to facilitate the passage of air to and from the throat and lungs. As the device receives the top and bottom teeth and fixes their relative position, natural mouth motions, including motion of the lower jaw, are prevented.
A device which effectively alleviates or prevents snoring is disclosed in my earlier U.S. Pat. No. 5,092,346 for a Dental Orthosis for Alleviation of Snoring, marketed under the name Snore Guard.RTM., the disclosures of which is incorporated herein by this reference. That structure includes an upper portion in the form of pair of parallel and substantially coextensive walls defining a trough corresponding in shape to the curvature of the patient's upper dental arch, for receiving the upper teeth of the patient. Once properly fitted, the device will snugly receive the front teeth and the premolars and remain positioned independent of natural motions of the lower jaw.
The lower portion of the '346 patent device is formed into a ramp structure whereby natural jaw motions result in the engagement of the lower teeth against the ramp, which will cam the lower jaw into a more forward position. An aperture in the device between the upper and lower portions facilitates the passage of air for mouth breathing and attracts the tongue forward. By inducing the lower jaw and tongue to a more forward position, the device induces a more open posterior airway in the patient, resulting in a significant reduction in snoring.
In contradistinction to the teachings of King, the structure of the '346 patent device does not fix the position of the upper and lower jaw and tongue. Instead, by an adroit arrangement of the structure, the device snugly attaches to the upper teeth and jaw, while allowing natural mouth movements including motions of the lower jaw and teeth, and tongue. That device is further distinguished in providing the ramp to engage the lower anterior teeth and induce forward movement of the lower jaw, resulting in the opening of the posterior airway.